New York and Baltimore – March 22, 2018 - Deerfield Management announced today that it has committed
$36 million of a $40 million Series A investment to advance Dracen Pharmaceuticals, Inc.’s novel immunometabolism
pipeline. Dracen, a private company developing proprietary anti-cancer drugs discovered at
the Johns Hopkins University and the Institute of Organic Chemistry and Biochemistry of the Czech
Academy of Sciences (IOCB Prague), will use this financing to progress its programs into clinical trials for
patients suffering from cancer.

Dracen will develop its platform of novel glutamine antagonists by building upon the immuno-metabolism
effects demonstrated in preclinical cancer models. Immuno-metabolism is the convergence of cancer
metabolism and immuno-oncology whereby agents disrupt the energy sources required to keep tumors
alive while simultaneously inducing the patient’s own immune system to fight cancer. Dracen intends to
develop its glutamine antagonists both in single-agent settings as well as in combination with immune
checkpoint inhibitors such as anti-PD-1 and anti-PD-L1.

“We are pleased to partner with Dracen and its founders from Johns Hopkins University,” said Jonathan S.
Leff, a Partner with Deerfield Management. “We see great potential for Dracen’s approach to deliver
improved outcomes for cancer patients and potentially extend the benefits of immuno-oncology
therapies.”

“We are excited to partner with Deerfield to advance our immuno-metabolism pipeline” remarked Thomas
M. Estok, Chief Executive Officer of Dracen Pharmaceuticals. “Deerfield’s engagement in our efforts helps
bring us closer to an important potential step forward in the treatment of cancer.”

About Dracen Pharmaceuticals

Dracen Pharmaceuticals, Inc. is a privately-funded biotech company developing proprietary glutamine
antagonists discovered at the Johns Hopkins University and the Institute of Organic Chemistry and
Biochemistry of the Czech Academy of Sciences (IOCB Prague). Dracen was founded by Johns Hopkins
University professors Barbara Slusher, MAS/PhD; Jonathan Powell, MD/PhD; and Rana Rais, PhD; together
with their IOCB Prague collaborator Pavel Majer, PhD to develop the novel glutamine antagonists for the
treatment of cancers as well as autoimmune and inflammatory diseases.

About Deerfield

Deerfield is an investment management firm committed to advancing healthcare through investment, information and philanthropy.